ORA-02266: unique/primary keys in table referenced by enabled foreign keys

Question

Hi,
I am trying to delete data from a table by dropping a partition. I have identified all the child tables by running the following command.
select 'select count(*) from '||table_name||' where employee_id = 100;'
from dba_constraints
where constraint_type='R'
and r_constraint_name in
(select constraint_name from dba_constraints
where constraint_type in ('P','U') and table_name='EMPLOYEE);
'SELECTCOUNT(*)FROM'||TABLE_NAME||'WHEREEMPLOYEE_ID_ID=100;'
select count(*) from PT_ORDERS where employee_id = 100;
select count(*) from PT_DEP where employee_id = 100;
select count(*) from PT_SKILLSET where employee_id = 100;
I dropped the partition for employee_id 100 in all of the child tables. The select count(*) returns 0 rows for each of the above.
When I try to run the below command on the EMPLOYEE table, I get 'ORA-02266: unique/primary keys in table referenced by enabled foreign keys'.
alter table EMPLOYEE drop partition EMP_ID_100;
I cant see why I am unable to drop this partition now as there is now child data in any of the referenced tables. Any suggestions or help on this would be greatly appreciated.
Thanks.
Rgs,
Rob

Answer 1

You should disable foreign key constraints first and drop partition. Deletion of rows or dropping partitions in childs don't work in this case
as you have the global dependency:
<PRE>
SQL> create table scott.t (x int primary key, y int)
2 partition by list (y) (
3 partition p_1 values(1), partition p_2 values(2))
4 /
Table created.
SQL> create table scott.t_c (x int references scott.t(x), y int)
2 partition by list (y) (
3 partition p_1 values(1), partition p_2 values(2))
4 /
Table created.
SQL> insert into scott.t values(1,1)
2 /
1 row created.
SQL> insert into scott.t values(2,2)
2 /
1 row created.
SQL> insert into scott.t_c values(1,1)
2 /
1 row created.
SQL> insert into scott.t_c values(2,2)
2 /
1 row created.
SQL> commit;
Commit complete.
SQL> alter table scott.t_c drop partition p_2;
Table altered.
SQL> alter table scott.t drop partition p_2;
alter table scott.t drop partition p_2
ERROR at line 1:
ORA-02266: unique/primary keys in table referenced by enabled foreign keys
SQL> select constraint_name from dba_constraints
2 where owner = 'SCOTT' and constraint_type = 'P'
3 and table_name = 'T';
CONSTRAINT_NAME
SYS_C0011058
SQL> select constraint_name from dba_constraints
2 where owner = 'SCOTT' and constraint_type = 'R'
3 and r_constraint_name = 'SYS_C0011058';
CONSTRAINT_NAME
SYS_C0011059
SQL> alter table scott.t_c disable constraint SYS_C0011059;
Table altered.
SQL> alter table scott.t drop partition p_2;
Table altered.
SQL> alter table scott.t_c enable novalidate constraint SYS_C0011059;
Table altered.
</PRE>
I guess you should consider such option as Referencial partitioning (with some restrictions).
Best wishes,
Dmitry.